Image Resizer

Making an image smaller throws away pixels, and you cannot get them back, but the result looks correct because the browser averages them properly rather than dropping them. Making an image larger invents pixels that were never there, so it goes soft. Resize down freely, resize up only when you have no better source.

Resizing changes the number of pixels. Compressing keeps the pixels and stores them less precisely. For a photo going onto a web page you usually want both: resize to the width it will actually be displayed at, then compress. Our image compressor handles the second half.

Match the space the image occupies, then double it for high density screens. A photo shown 600 pixels wide wants a 1200 pixel file. Anything beyond that is bytes your visitors download and never see.

For photographs on a web page, yes. It is typically 25 to 35 percent smaller than JPEG at the same visual quality and every current browser reads it. Keep JPEG for anything that has to open in older software.

PNG is lossless, so it stores every pixel exactly. That is the right choice for logos, screenshots and anything with transparency, and the wrong one for a photograph, where lossless means enormous.

No. The file never leaves your browser. You can watch the network panel of your developer tools and see that no request is made, which is the point of doing this work on the client.

Only what your browser's memory allows. Very large photographs from a modern camera work, though the canvas has a maximum dimension in some browsers, so a truly enormous image can fail. If it does, resize it in two steps.

No, and that is worth knowing in both directions. Redrawing through a canvas drops all metadata including GPS, which is good for privacy and bad if you wanted to keep the camera information. To read or strip metadata deliberately, use our EXIF viewer.